Scottish nationalist ministers in Edinburgh have been accused of illegally trying to seize control of fish stocks after they imposed a unilateral ban on the sale of fishing quotas to non-Scottish skippers.

The Scottish National party's (SNP) fisheries minister, Richard Lochhead, has introduced a moratorium on the sale of quotas held by Scottish trawlers while he carries out a controversial review of fishing licences and quota controls which could greatly restrict the rights of English vessels to fish in Scottish waters.

His moratorium provoked a furious response from ministers in the UK government and from fishermen's leaders in both England and Scotland, who accused Lochhead of breaching European law and creating an artificial conflict over fishing rights to stir up a nationalist backlash.

Barries Deas, the chief executive of the York-based National Federation of Fishermen's Organisations, said: "This move is provocative, highly irresponsible and probably illegal," he said.

"There is no such thing as Scottish or English quota. There is UK quota. If the Scottish executive has any doubts over this, a brief telephone call to the European commission should allay any doubts."

The UK's fisheries minister, Jonathan Shaw, has formally warned the Scottish executive he believes the moratorium is illegal and had "significant concerns" that the quota reforms breached its powers under devolution, which gives Scottish ministers limited rights to decide their own fisheries policy.

Lochhead said his reforms were intended to protect a vital industry under intense pressure from cuts in quotas, competition and soaring fuel costs. He wants to overhaul the current quota rules to favour Scottish-based skippers and fleets – which currently control 70% of the UK's fisheries, and implied he wants to permanently restrict access to non-Scottish trawlers.

Fishing was a "national asset" for Scotland, he claimed. "It is vital that we take steps to safeguard the historic rights for future generations," he said.

The Scottish government was also trying to withdraw from the EU common fisheries policy, he said. Ministers in London said that this was impossible, since it is the UK government which was the member state, not Scotland.

Jim Murphy, the Foreign Office minister for Europe, said leaving the common fisheries policy contradicted the SNP's claims that an independent Scotland would be a full member of the EU. "It's time they were honest with the people of Scotland - their policies just don't add up," he said.

Scottish fishermen's leaders said the proposals would put small, inshore fleets in conflict with larger deep sea trawlers but could also make it impossible for a fisherman in south-west England to lease any fishing from a colleague in Scotland or sell their quota freely.

George MacRae, the secretary of the Scottish White Fish Producers' Association, said the moratorium on selling quotas was restricting "a perfectly correct and legitimate trading activity. There is every reason to suggest that the moratorium is illegal and enforceable."